1. Field of the Invention
This invention relates to an antiplaque oral composition containing an alkoxy substituted 2-hydroxy benzophenone which exhibits heightened antibacterial efficacy against plaque causing oral bacteria.
2. The Prior Art
Dental plaque is a soft deposit which forms on teeth as opposed to calculus which is a hard calcified deposit on teeth. Unlike calculus, plaque may form on any part of the tooth surface, particularly at the gingival margin. Hence, beside being unsightly, it is implicated in the occurrence of gingivitis.
It is difficult to predict the efficacy of antibacterial agents when incorporated in oral compositions. For example, cationic antibacterial materials such as chlorhexidine, benzthonium chloride and cetyl pyridinium chloride have been used by the art as antibacterial antiplaque agents in oral compositions. However, such agents are generally not effective when there is also present anionic surfactants required for the effective performance of oral compositions such as toothpaste and mouthrinses. Nonionic antibacterial materials are compatible with anionic ingredients in oral compositions and nonionic halogenated hydroxydiphenyl ethers such as Triclosan have been effectively employed in oral compositions as antibacterial antiplaque agents when admixed with neutral materials such as humectants, abrasives and thickeners used in the formulation of oral compositions. Notwithstanding the antibacterial efficacy of Triclosan, there is a continuing interest in the oral composition field for antibacterial agents which are compatible with anionic surfactants present in such compositions.
It is known to the art, U.S. Pat. No. 3,993,779, that 2-hydroxy benzophenone, and certain alkyl, benzene, halogen and cyclohexyl-substituted 2-hydroxy benzophenones have antibacterial action and are suitable for use as preservatives and disinfectants.
Japanese Patent 03170414 discloses the use of 2-hydroxybenzophenone in toothpaste, for the prevention and treatment of periodontal disorders. Although effective for this purpose, the antiplaque efficacy of the toothpaste containing the hydroxybenzophenone compound is limited and an improvement in its efficacy is required for acceptability in commercial use.